1. Field of the Invention
The present invention relates to a biometric information measuring apparatus for measuring biometric information of pulse, heart beat or the like.
2. Description of the Prior Art
In a background art, there has been developed a biometric information measuring apparatus for detecting a biometric signal of a person, such as a pulse signal, a heart beat signal or the like, and for measuring biometric information in correspondence with the biometric signal, such as a pulse number, a heartbeat number or the like per unit time.
When the biometric signal is detected, noise by physical movement or the like of a measured person is brought about and therefore, a measurement error produced by the noise or the like needs to be restrained.
In a biometric information measuring apparatus of a pulsimeter, a heart beat meter or the like of a background art, when the pulse number or the heart beat number is calculated from the pulse signal or the heart beat signal, fast Fourier transformation (FFT) is utilized (refer to, for example, JP-A-2003-265441).
However, according to the invention described in JP-A-2003-265441, when the signal waveform is disturbed by the physical movement or the like, as a result of FFT processing, other than a base line intended to be calculated inherently, a noise baseline proximate to a direct current component emerges at a high level and accurate measurement becomes difficult.
In order to prevent this, as in the invention described in JP-A-2003-265422, a high degree algorism needs to be used and therefore, there poses a problem that the processing becomes complicated.
The invention has been carried out in view of the above-described problem and it is an object of the present invention to be able to measure biometric information utilizing a highly accurate and simple apparatus and process.